There is momentum in the telecommunications market to move towards carrier hosted solutions. In a carrier hosted solution, the telecommunications carrier offers communications capability to customers as a service rather than as a product. To provide a high value service, carriers would like to provide network management services such as fault management, performance monitoring and device configuration and maintenance to customers not only in respect of the communications equipment in the carrier network, but also in respect of communications equipment in the customer network. For example, in a Voice over Internet Protocol (VoIP) solution, an enterprise or residential network will include terminal devices with which users may make and receive voice or other media calls. Carriers would like to provide management services in respect of these devices using network management systems in the carrier network.
Conventionally, operational information for use in network management systems and control information sent by network management systems is communicated using standard protocols such as the Simple Network Management Protocol (SNMP) or Syslog. However, in a carrier hosted solution, there is a problem in communicating SNMP or Syslog messages between the customer network and the carrier network. Typically, Network Address Translators (NATs) and/or firewalls are deployed to provide IP address resolution and security between the internal customer network and the external carrier network. SNMP or Syslog messages from the enterprise or residential network will not generally be able to traverse the NAT or firewall.
It is possible to maintain a specific NAT bind or firewall pinhole for each managed device in the customer network to allow the SNMP or Syslog messages to traverse the NAT or firewall. However, this is undesirable for the following reasons. Firstly, by maintaining additional binds or pinholes, the security risk posed to the customer network is increased. Secondly, where NATs are used, capacity is reduced since port numbers on the external IP address are limited and hence there is only a limited number of internal IP address that may be supported by a NAT. Thirdly, the translation of various internal IP address and port number combinations in the customer network to an external IP address and port number may effect the operation of standard management protocols which use defined port numbers for various functions.
An object of the present invention is too overcome or ameliorate the problems described above.